Objective: To reduce transmission of Onchocerca volvulus by the vector Simulium neavei in Kabarole district, Uganda. Methods: The study began in 1996 and the method used included annual community-based treatment of the population with ivermectin (Mectizan) tablets and vector control measures using the organophosphorous larvicide temephos. For monitoring purposes, S. neavei flies were caught and examined for infections with L1/L2 or with infective L3 larvae of O. volvulus. DNA analysis was done to correctly identify larvae of the species O. volvulus. River crabs Potamonautes aloysiisabaudiae were examined for the phoretic immature stages of S. neavei. Results: Transmission of onchocerciasis was intense in this foci at the beginning of the control program, as indicated by the high pre-treatment infection rates of the S. neavei population. (125.3 infective larvae of O. volvulus in 1000 parous flies and river crabs positive for larvae of S. neavei often exceeded 50%). After the intervention program was implemented, flies were gone and no positive river crabs were detected even during the last monitoring survey in 2000 which tested 300 river crabs caught. Conclusions: The control of the onchocerciasis vector S. neavei was effective and has so far eliminated transmission of O. volvulus from a focus where some 50,000 people are at risk of infection.This has positive implications for the agricultural production in this area: 1) people free of onchocerciasis have a higher work output, and 2) new arable land is available and used for cultivation because high biting densities of Simulium flies have been reduced.
Learning Objectives: N/A
Keywords: Disease Prevention, Developing Countries
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.